Fire-proof paper or board



(No Model.)l

J. G. MERRILL. PIRE PROOP PAPER OR BOARD.

No. 357.424. Patented Aug. 2, 188?.

UITED STATES PATENT OFFICE.

JONATHAN MERRILL, O F QUINCY, ASSIGNOR OF ONE-HALF 'IOv MOODY MERRILL, OF BOSTON, MASSACHUSETTS.

Flan-Pecci PAPER on BOARD.

' SPECIFICATION forming part of Letters Patent 10.367,424, dated August 2, 1887.

.Application filed J'uly 26, 1886.

.T a/ZZ whom, it may concern.'

Be it known that I, JONATHAN G. MERRILL, of Quincy, in the county of Norfolk and State of Massachusetts, a citizen of the United States,

have invented a new and useful Improvement rin explaining its nature.

in Fire-Proof Paper or Board, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming a part of this specification,

The invention relates to a tire-proof board or paper comprising a base or body of paper or board material, and a layer or coating of asbestus or other fire-resisting material applied to the rst-named body or layer at the time that it is manufactured, so that the man ufactured 'article when completed comprises a base or layer of one fireresistng material su rface covered with a layer or coating of another material of a greater lire-resisting quality.

In the drawings, Figure l represents in section a part of a paper-making machine, showing the base or body of the fire-proof material passing through it. Fig. 2 is a view also showing or layer of asbestus.

ing in-` section ai ypart of the paper-making '.machine, and illustrating the applicationto greater Iire-resisting properties than those generally used, and I prefer a mixture o r composition containing about sixty per cent. vegetable ber, twenty per cent. asbestus, ten per cent. alum oreopperas,and ten per cent. coloring-matter, preferably plumbago or lampblack or Venetian red.` These ingredients are intimately mixed or incorporated'together. This composition is, then run through the papermachine in the ordinary way; but instead of passing through the driers it is rolled and immediately passed through the machine again,

serial ivo. 209.045. m0 model.)

and upon the second passage of this base or layer a composition having greater fire-resisting qualit-ies is fed therein by suitable devices and united thereto by the paper-making ma; ohinery, it being spread thereon and fed thereto in the same manner that it would be formed or made into a web of paper. The

compound paper thus made is then passed through rolls and dried, andthe paper is ready for any subsequent treatment.

rIhe composition which I prefer to employ for furnishing the higher fireresistin`g property comprises asbestus mixed with sufficient glue, starch, or other similar ingredient to keep it together While it is being applied; but

from its nature it is obvious that it does not possess the strength th at Ithe first-named composition, or composition for forming the base or firstlayer, possesses. It will therefore be seen'that I obtain by the first layer principally strength, and by thesecond layer principally high fire or heat resisting or protectv ing properties, which, being intimatelyjoined to the rstiayer, is held, supported, and sustained thereby, so that a very strong, solid,

durable, and cheapproduct is obtained. After the compound paper has thus been made it may be further subjected to other treatment to increase its tire-resisting properties-such,

When a board or paper of two layers'or piecesis made,I preferto ar- 'range them so thatY the surfaces' having the.

greater fire-resisting property` shall come upon the'outside,

In Fig. 2 I'have represented a small section of a paper-making machine representing the first section or part of the compound paper as having been made and rolled, and being again movedth-rough the machine to beunited with the second layer, or' the higher tire-resisting material; and A.v represents this first-named layer and A the second-named layer.

In Fig. 4,' a represents a coating of silicate. of soda applied to'thesecond layer of the compound paperor board A. A

In Fig. 5 I have represented two -pieces of the compound paper or board secured together IOC) o ack, and having,` liicateof-soda faces. This compound paper or board is applicable as a protection from fire or high heat, and to this end buildings, apartments, rooms, or articles may be coated therewith.

It is manifest that the proportions given herein may be modified without departing from the spirit of the invention, and that there are many equivalent materials which may be nseor those herein named; and I prefer to, in soiie instances, mix tale or powdered chalk with the silicate of soda, and in other instances chloride of zinc; but whichever materials are employed in making this compound paper or board, the base should be made of a fire-resisting composition7 and the covering should be made of a reprotecting com positio n-that is, a composition thatshall form, when submitted to great heat, a continuous layer that shall 2o protect thecfirc-resisting material which it coats.

Having thus fully described my invention, I claim and desire to secure by Letters Patent of the United States- The process of making compound fire or heat resisting paper or board, consisting,rst, in making a web of paper or paper-like material, but not drying the same, and, second,

immediately returning it th rough the mill,a11d

at that time incorporating therewith or forming thereon a second web of heat or fire reslsty ing material, substantially as described.

JONATHAN G. MERRILL.

Witnesses: F. F. RAYMoND, 2d,

FRED. B. DoLAN. 

